BACKGROUND: Previous studies have investigated various types of postural biofeedback devices on different body regions to improve posture; however, they focused only on healthy adults without a history of chronic musculoskeletal disorders. In addition, those postural biofeedback devices used in previous studies are often designed for experimental research. The designs are usually bulky with many wires, which is not practical for everyday use. RESEARCH QUESTION: The aim of this study was to determine the immediate effect of a commercially available real-time postural biofeedback device on spinal posture, muscle activity, and perceived pain severity in adults with neck pain. METHODS: 21 adults who had chronic or recurrent nonspecific neck pain for more than 3 months and whose pain was induced or aggravated by prolonged computer work were enrolled in this study. Spinal posture (head tilt, neck flexion, cervical and thoracic angles), muscle activity (cervical erector spinae, upper trapezius, and thoracic erector spinae), and self-reported neck and shoulder pain were measured during computer typing tasks, with and without biofeedback. RESULTS: Compared with the non-biofeedback condition, the biofeedback condition significantly decreased neck flexion, upper cervical, and lower thoracic angles and lowered the activity of the cervical erector spinae. Self-reported neck pain was not influenced by the application of biofeedback, but significantly increased over the 1-hour typing task. SIGNIFICANCE: The application of a commercially available wearable real-time biofeedback device improves sitting posture and reduces muscular activity in adults with nonspecific neck pain during computer work. Future studies should examine the long-term effects of wearable real-time postural biofeedback devices for prevention and management of neck pain.